| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.samza.clustermanager; |
| |
| import java.util.Set; |
| import org.apache.samza.annotation.InterfaceStability; |
| |
| /** |
| * This interface gets fault domain information of all hosts that are running in the cluster, |
| * from the cluster manager (Yarn/Kubernetes/etc.). |
| * It also provides other functionality like exposing all the available fault domains, checking if two hosts belong to |
| * the same fault domain, and getting the valid fault domains that a container can be placed on (for ex: based on standby constraints). |
| * The host to fault domain map used here will always be cached and only updated in case the AM dies or an active |
| * container is assigned to a host which is not in the map. |
| * This is not thread-safe. |
| */ |
| @InterfaceStability.Unstable |
| public interface FaultDomainManager { |
| |
| /** |
| * This method returns all the fault domain values in a cluster, for all hosts that are healthy, up and running. |
| * This set might not be up to date with the current state of the cluster, as its freshness is an implementation detail. |
| * @return a set of {@link FaultDomain}s |
| */ |
| Set<FaultDomain> getAllFaultDomains(); |
| |
| /** |
| * This method returns the fault domain a particular host resides on based on the internal cache. |
| * @param host the host |
| * @return the {@link FaultDomain} |
| */ |
| Set<FaultDomain> getFaultDomainsForHost(String host); |
| |
| /** |
| * This method returns true if the fault domains on which these two hosts reside are exactly the same, false otherwise. |
| * @param host1 hostname |
| * @param host2 hostname |
| * @return true if the hosts exist on the same fault domain |
| */ |
| boolean hasSameFaultDomains(String host1, String host2); |
| |
| } |